Conceptualized data structure for sustainability assessment of energy and material flows: example of a PV life cycle

Traditional linear value creation is showing its limits in terms of resilience and sustainability thus underlining the need for alternative business mind-sets such as circular thinking. The current unsustainable use of natural resources and their environmental impacts over the full life cycle represent one of the major challenges of the 21st century. The continuous increase in raw material extraction and processing, fueled by global population growth and increasing production and consumption patterns will lead to surpassing the planetary boundaries, resulting irreversibly in ecological, economic, and social consequences. In the future, value chains need to be transformed into sustainable value creation cycles to ensure sustainable consumption and production. Well-established sustainability assessment methods like Life Cycle Assessment (LCA) evolve towards assessing not only production but also the whole value creation cycle. However, modelling of closed loops requires a range of specifications that are often not accounted for in current LCA literature. We identified those challenges based on literature search and own findings and discuss their implications for assessing the ecological sustainability of photovoltaic (PV) value creation cycles. Overall, the lack of data on material quantity, (sub-)product quality loss and recycling processes is a key barrier in modelling circular value chains in PV. Addressing this challenge by collecting targeted information during the use and end-of-life phases while selecting adapted allocation and modelling approaches are the first steps to identify ecologically sound circularity strategies.